Tpo primer

Abstract

A composition in the form of a solution or dispersion, comprising an anhydride-modified polyolefin, an anhydride-modified styrenic block copolymer, and an isocyanate-containing crosslinker, wherein the anhydride-modified polyolefin and anhydride-modified styrenic block copolymer are present in a total amount in the range of 7% to 18% by weight in total, based on the composition, and in a weight ratio of anhydride-modified polyolefin to anhydride-modified styrenic block copolymer which is in the range of 2:1 to 6:1; the weight ratio of isocyanate-containing crosslinker to the sum of anhydride-modified polyolefin plus anhydride-modified styrenic block copolymer is in the range of 0.2:1 to 0.5:1; and the solvent comprises a ketone as first solvent and an alkylbenzene or an alkane solvent. The compositions are useful for adhering TPO to TPU, polyester or PU. The composition can be used in a process of bonding a first part or coating of a TPO to a second part or coating of TPU, polyester or PU, using heat and optionally pressure, wherein the adhesion has improved peel strength.

1 . Use of a composition in the form of a solution or dispersion in a solvent, comprising
 an anhydride-modified polyolefin,   an anhydride-modified styrenic block copolymer, and   an isocyanate-containing crosslinker,   wherein   the anhydride-modified polyolefin and anhydride-modified styrenic block copolymer are present in a total amount in the range of 7% to 18% by weight in total, based on the composition, and in a weight ratio of anhydride-modified polyolefin to anhydride-modified styrenic block copolymer which is in the range of 2:1 to 6:1;   and   the solvent comprises as a first component a ketone solvent which is one or more aliphatic C 5 -C 8 -ketones each adhering to the following formula:   
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are each independently selected from the group consisting of methyl, ethyl and branched or unbranched C 3 -C 4  alkyls, provided that the total carbon number of R 1  and R 2  is in the range of 4 to 7; or wherein R 1  and R 2  taken together form an alkylene bridge —(CH 2 ) m —, wherein m is an integer in the range of 4 to 7; and comprises as a second component a C 6 -C 8 -alkane solvent; 
         for promoting adhesion of TPO to polyester; 
         characterized in that 
         the composition comprises an isocyanate-containing crosslinker having an NCO content of from 10 to 35% by weight, based on the. Furt isocyanate-containing crosslinker, as determined according to standard DIN 11909 (2007), and in a peel strength-enhancing amount of the isocyanate-containing crosslinker which is in the range of 2 to 6% by weight, based on the overall composition; and 
         the weight ratio of the isocyanate-containing crosslinker to the sum of anhydride-modified polyolefin plus anhydride-modified styrenic block copolymer in the composition is in the range of 0.2:1 to 0.5:1. 
       
     
     
         2 . The use of  claim 1 , wherein the anhydride-modified polyolefin is obtainable either
 1) by grafting a polyolefin which is selected from the group consisting of polyethylene, an ethylene-α-olefin-copolymer (wherein the α-olefin is selected from the group consisting of propene, 1-butene, 1-pentene, 1-hexene, 1-heptene and 1-octene) and polypropylene; with an olefinic anhydride selected from the group consisting of
 maleic anhydride,
 a Diels-Alder reaction product of maleic anhydride with buta-1,3-diene, cyclopentadiene or cyclohexa-1,3-diene; and 
 a reaction product of maleic anhydride with an α-olefin selected from the group consisting of propene, 1-butene, 1-pentene, 1-hexene, 1-heptene and 1-octene; or 
 
   2) by copolymerizing an olefinic anhydride as defined above with ethylene and/or an α-olefin as defined above.   
     
     
         3 . The use of  claim 1  or  2 , wherein the styrenic block copolymer within the anhydride-modified styrenic block copolymer is selected from the group consisting of SBS (styrene-butadiene-styrene), SIS (styrene-isoprene-styrene) and SEBS (styrene-(ethylene-co-butylene)-styrene). 
     
     
         4 . The use of anyone of  claims 1  to  3 , wherein the isocyanate-containing crosslinker is
 i) a reaction product obtainable by first reacting aniline with formaldehyde in presence of hydrochloric acid catalyst, and then reacting the obtained mixture of homologous aniline-formaldehyde adducts with phosgene; or 
 ii) is selected from the group consisting of 2,4-tolylenediisocyanate, 2,6-tolylenediisocyanate, hexamethylenediisocyanate, m-xylenediisocyanate, p-xylenediisocyanate, 2 diisophorone diisocyanate and diphenylether-2,4,4-triisocyanate; or 
 iii) an uretidinedione- and/or 2,4,6-trioxotriazine-containing oligomer of 2,4-tolylenediisocyanate and/or 2,6-tolylenediisocyanate. 
 
     
     
         5 . The use of anyone of  claims 1  to  4 , wherein the first component of the solvent is cyclohexanone and the second component of the solvent is methylcyclohexane. 
     
     
         6 . The use of  claim 5 , wherein
 the weight ratio of methylcyclohexane to cyclohexanone is in the range of 15:1 to 30:1.   
     
     
         7 . The use of  claim 6 , wherein the alkylbenzene solvent is a mixture of xylenes and ethylbenzene in a weight ratio of 3:1 to 2:1. 
     
     
         8 . The use of anyone of  claims 1  to  7 , wherein the solvent consists to at least 95% by volume of ketone solvent as first component and C 6 -C 8 -alkane solvent as second component. 
     
     
         9 . The use of anyone of  claims 1  to  8 , wherein the TPO is a TPO part in the form of a sheetlike material with a planar first surface having a critical surface energy in the range of 28 to 38 mN/m at 25° C. 
     
     
         10 . The use of anyone of  claims 1  to  7 , wherein the anhydride-modified polyolefin is as defined in  claim 2 ; the anhydride-modified styrenic block copolymer is as defined in  claim 3 ; or the isocyanate-containing crosslinker is as defined in  claim 4 . 
     
     
         11 . A composition in the form of a solution or dispersion in a solvent, comprising
 an anhydride-modified polyolefin,   an anhydride-modified styrenic block copolymer, and   an isocyanate-containing crosslinker,   wherein   the anhydride-modified polyolefin and anhydride-modified styrenic block copolymer are present in a total amount in the range of 7% to 18% by weight in total, based on the composition, and in a weight ratio of anhydride-modified polyolefin to anhydride-modified styrenic block copolymer which is in the range of 2:1 to 6:1;   the weight ratio of isocyanate-containing crosslinker to the sum of anhydride-modified polyolefin plus anhydride-modified styrenic block copolymer is in the range of 0.2:1 to 0.5:1; and   the solvent comprises as a first component a ketone solvent which is one or more aliphatic C 5 -C 8 -ketones each adhering to the following formula:   
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are each independently selected from the group consisting of methyl, ethyl and branched or unbranched C 3 -C 4  alkyls, provided that the total carbon number of R 1  and R 2  is in the range of 4 to 7; or wherein R 1  and R 2  taken together form an alkylene bridge —(CH 2 ) m —, wherein m is an integer in the range of 4 to 7; and comprises as a second component an alkylbenzene solvent which is a mixture of xylenes and ethylbenzene. 
       
     
     
         12 . The composition of  claim 11 , wherein the anhydride-modified polyolefin is obtainable either
 1) by grafting a polyolefin which is selected from the group consisting of polyethylene, an ethylene-α-olefin-copolymer (wherein the α-olefin is selected from the group consisting of propene, 1-butene, 1-pentene, 1-hexene, 1-heptene and 1-octene) and polypropylene; with an olefinic anhydride selected from the group consisting of
 maleic anhydride, 
 a Diels-Alder reaction product of maleic anhydride with buta-1,3-diene, cyclopentadiene or cyclohexa-1,3-diene; and 
 a reaction product of maleic anhydride with an α-olefin selected from the group consisting of propene, 1-butene, 1-pentene, 1-hexene, 1-heptene and 1-octene; or 
   2) by copolymerizing an olefinic anhydride as defined above with ethylene and/or an α-olefin as defined above.   
     
     
         13 . The composition of  claim 11  or  12 , wherein the styrenic block copolymer within the anhydride-modified styrenic block copolymer is selected from the group consisting of SBS (styrene-butadiene-styrene), SIS (styrene-isoprene-styrene) and SEBS (styrene-(ethylene-co-butylene)-styrene). 
     
     
         14 . The composition of anyone of  claims 11  to  13 , wherein the isocyanate-containing crosslinker is
 i) a reaction product obtainable by first reacting aniline with formaldehyde in presence of hydrochloric acid catalyst, and then reacting the obtained mixture of homologous aniline-formaldehyde adducts with phosgene; or 
 ii) is selected from the group consisting of 2,4-tolylenediisocyanate, 2,6-tolylenediisocyanate, hexamethylenediisocyanate, m-xylenediisocyanate, p-xylenediisocyanate, diisophorone diisocyanate and diphenylether-2,4,4-triisocyanate; or 
 iii) an uretidinedione- and/or 2,4,6-trioxotriazine-containing oligomer of 2,4-tolylenediisocyanate and/or 2,6-tolylenediisocyanate. 
 
     
     
         15 . The composition of anyone of  claims 11  to  14 , wherein the first component of the solvent is cyclohexanone. 
     
     
         16 . The composition of  claim 15 , wherein
 the anhydride-modified polyolefin and anhydride-modified styrenic block copolymer are present in a total amount in the range of 7% to 11% by weight in total, based on the composition, and in a weight ratio of anhydride-modified polyolefin to anhydride-modified styrenic block copolymer which is in the range of 2:1 to 6:1;   the isocyanate-containing crosslinker is a reaction product obtainable by first reacting aniline with formaldehyde in presence of hydrochloric acid catalyst, and then reacting the obtained mixture of homologous aniline-formaldehyde adducts with phosgene to convert the aromatic amine groups to isocyanate groups, and this isocyanate-containing crosslinker is present in a weight ratio of 0.2:1 to 0.5:1 with respect to the sum of anhydride-modified polyolefin plus anhydride-modified styrenic block copolymer; and   the weight ratio of alkylbenzene solvent to ketone solvent is in the range of 6:1 to 3:1.   
     
     
         17 . The composition of  claim 16 , wherein the alkylbenzene solvent is a mixture of xylenes and ethylbenzene in a weight ratio of 3:1 to 2:1. 
     
     
         18 . The composition of anyone of  claims 11  to  17 , wherein the solvent consists to at least 95% by volume of ketone solvent as first component and alkylbenzene solvent as second component. 
     
     
         19 . Use of the composition of anyone of  claims 11  to  18 , for promoting adhesion of TPO to TPU, polyester or PU. 
     
     
         20 . The use of  claim 19 , wherein the anhydride-modified polyolefin is as defined in  claim 2 ; the anhydride-modified styrenic block copolymer is as defined in  claim 13 ; or the isocyanate-containing crosslinker is as defined in  claim 14 . 
     
     
         21 . A process for bonding a first surface of a first part of a TPO to a second surface of a second part of a polyester or a TPU using heat and optionally pressure, comprising the steps of:
 applying to the first and/or the second surface a composition of anyone of  claims 11  to  18 ; and   bonding composition-coated first surface and second surface, or first surface and composition-coated second surface, or composition-coated first surface and composition-coated second surface, together using heat and optionally pressure.   
     
     
         22 . The process of  claim 21 , wherein during bonding of first and second surface the first and second surfaces are heated to a temperature which is 20 to 50° C., preferably 30° C. to 40° C., above the melting point of the TPO of the first part, that melting point being determined by differential scanning calorimetry (DSC) according to norm ISO 11357-3. 
     
     
         23 . A process for bonding a first coating of a TPO by extrusion and melt-coating to a second surface of a second part of polyester or TPU, comprising the steps of:
 applying a composition of anyone of  claims 11  to  18  to the second surface; and   extruding and melt-coating the TPO onto the combination- or composition-coated second surface.   
     
     
         24 . A process for bonding a second coating of a TPU to a first surface of a first part of TPO by extrusion and melt-coating, comprising the steps of:
 applying a composition of anyone of  claims 11  to  18  to the first surface; and   extruding and melt-coating the TPU onto the composition-coated first surface.   
     
     
         25 . A process for bonding a second coating of a crosslinked PU to a first surface of a first part of TPO by heat and optionally pressure, comprising the steps of:
 applying a crosslinkable TPU onto the first surface a composition of anyone of  claims 11  to  18 ; and   bonding of the crosslinkable TPU to the composition-coated first surface by heat and optionally pressure, whereby simultaneously the crosslinkable PU is crosslinked to crosslinked PU.   
     
     
         26 . The process of  claim 25 , wherein the crosslinkable PU is applied as a solution in a solvent and before bonding by heat and optionally pressure the solvent is evaporated. 
     
     
         27 . The process of anyone of  claims 21  to  26 , wherein the composition is applied to the first surface and/or to the second surface in a dry mass amount of 10 to 40 g per square metre of the total area of first surface and/or second surface.